Philippine Environment Secretary Regina Lopez increased her attacks on the mining sector in the Philippines by ordering a ban on openpit mining.

Lopez has been at odds with the sector for months, first ordering the closure of more than half the mines operating in the country saying the industry has caused extensive environmental damage to the county.

Reuters reported that she is an outspoken environmentalist-turned-regulator who faces a confirmation hearing in Congress that could lead to her removal as minister after a storm of complaints from pro-mining groups.

Lopez said it was within her prerogative to ban the practice of openpit mining, which is allowed under Philippines mining law.

“Each openpit is a financial liability for government for life,” she told a media briefing. “It kills the economic potential of the place.”

The ban will take effect immediately but will not cover existing mines, she said.

Mining is a contentious issue in the largely underexplored Southeast Asian country after past examples of environmental mismanagement.

Lopez in February ordered the permanent closure of 22 of 41 operating mines in the world’s top nickel ore supplier and later canceled dozens of contracts for undeveloped mines to protect water resources.

Miners have argued her actions are illegal and no mine has yet been closed as companies pursue an appeals process that can only be settled by President Rodrigo Duterte.

The Chamber of Mines of the Philippines described her latest move as "absurd."

“With this openpit ban, she is essentially banning the mining of shallow ore deposits that can only be extracted using openpit mining,” said Chamber spokesman Ronald Recidoro.

The ban would halt the $5.9 billion Tampakan copper-gold project in South Cotabato province in Mindanao island, the nation's biggest stalled mining venture.

Tampakan failed to take off after the province where it is located banned openpit mining in 2010, prompting commodities giant Glencore Plc to quit the project in 2015.

There are currently 14 openpits in the country, 10 of them abandoned, said Lopez, who flew to several mining sites in recent weeks to inspect them.

Lawmakers will resume hearings on Lopez's appointment on May 2 after sessions in March when pro-mining groups assailed her capacity as minister.

Lopez said she was imposing the ban now because she was unsure of the outcome of the hearings.